In the small Australian dragon (agamid) lizard Tympanocryptis tetraporophora mean snout-vent length (SVL) does not differ significantly between the sexes within the species as a whole. However, in a large sample from Sturt National Park, in northwestern New South Wales, males are larger than females both in snout-vent length and in mass. Large specimens are notably lacking from collections made during the coolest time of year.
The number of premaxillary teeth is not correlated with head size. However, the number of acrodont teeth on the maxilla and dentary increases with head size.
The modal number of presacral vertebrae is 23. There is no sexual dimorphism in either the number of postsacral vertebrae or the number of postsacral vertebrae with transverse processes. Hyperphalangy occurs in 3.2% of specimens. Gross variation in the sacral vertebrae occurs in 5.3% of specimens.
For allometric analysis, two samples were considered: specimens from Stud National Park and all other specimens. Head length and hind limb length are each in negative allometry with snout-vent length in both samples. However, tail length is in isometry in both sexes in the Sturt sample but in positive allometry in males and negative allometry in females in the oUler specimens. Mass is in negative allometry with snout-vent length in males but in isometry in females in the Sturt sample. The residual variances around the regression are not significantly different between the sexes for head length, hind limb length and tail length in the Sturt sample, but the variances are significantly higher for females than for males for head length and hind limb length in the other specimens.
Ventral colours include both pale salmon and yellow hues. The salmon colour tends to diminish and the yellow colour to increase with increasing size. Females lack pale dorsal longitudinal stripes more often than males, perhaps because larger females lose the stripes whereas larger males do not. Only mature females 255 mm SVL are totally patternless, i.e., they lack both pale stripes and dark blotches.
Males and females become sexually mature at a SVL of approximately 42 mm and 46 mm. respectively. In the Sturt sample, testis size is much larger in spring that in autumn. In the species as a whole, reproduction occurs between early spring and mid-autumn. Females with yolking follicles or oviducal eggs range in size from 46.5 to 72.0 mm SVL with a mean of 58.0mm. Clutch size ranges from 1 to 14 with a mean of 8.1. Clutch size is positively correlated with SVL.
Males are generally more common than females in collections, but the difference is statistically significant only among mature specimens. Comparisons are made with other Australian dragons.